Definition
In Roman and medieval English law, *duplicare* means to double or repeat; specifically, to execute a legal instrument in two parts so that each party to the transaction holds an original copy. The term appears most often in connection with indentures and bilateral charters where mutual obligations required that both parties possess an authenticated record of the agreement. A *conventio duplicata* — a duplicate covenant or agreement — was the standard formal product of this practice.
Common Language
Modern common usage (Wiktionary): *Duplicare* is Latin, surviving in English through derivatives such as "duplicate" and "duplication," meaning to make an exact copy or repeat something.
Historical common usage (Webster's 1913): "Duplicate" — one of two things exactly alike; a copy corresponding to an original.
The gap between ordinary and legal meaning here is subtle but important. Common usage treats a duplicate as a secondary copy made from a primary original. The legal practice captured by *duplicare* operated differently: both instruments were originals, executed simultaneously with equal authority. Neither was a copy of the other. A researcher who imports the modern sense — copy derived from an original — will misread what medieval conveyancing documents were doing.
Core Elements
The practice of *duplicare* in medieval conveyancing involved:
1. A bilateral or mutually obligating instrument (charter or covenant involving two parties).
2. Simultaneous execution in two parts, each part being a full and valid original.
3. Distribution so that each party retained possession of one part, providing both parties equal documentary security.
4. The duplicated form was the expected and proper formality when the charter was "common" — that is, when it contained mutual covenants binding both parties.
Why It Matters in Research
Researchers working in medieval English legal records or early conveyancing documents need to understand *duplicare* to correctly interpret references to charter execution practice. The term explains why surviving records sometimes show two instruments of apparently identical content: both were intentional originals, not a principal and a copy.
The concept connects directly to the development of the indenture as a conveyancing form. Indentures — documents whose physical edge was cut or indented so that the two parts could later be matched — solved the same problem *duplicare* addressed: securing both parties with an original. Researchers tracing the history of indentures back through Latin records will encounter *duplicare* and *conventio duplicata* as conceptual predecessors, and should not treat these terms as referring to a copy-original relationship.
Burrill's citation to Bracton (fol. 33b) and Fleta (lib. 2, c. 64, § 2) indicates this was a formal rule of practice, not merely a convenience. A charter involving mutual covenants *ought to* be duplicated — the language in Bracton is prescriptive. This suggests that a single-instrument bilateral charter might raise questions of completeness or irregularity in contemporary practice.
For corpus researchers: *duplicare* appears almost exclusively in Latin legal texts and glossaries of medieval English law. It will not appear in post-medieval English-language statutes or common law reports under this name; its functional successor vocabulary is "indenture," "counterpart," and "duplicate original." Searching for *duplicare* or *duplicari* in Latin source texts yields conveyancing treatises and formularies, not pleading records.
Historical Dictionary Support
Burrill provides a compact and accurate treatment. His entry captures the essential technical meaning — execution in two parts for mutual bilateral instruments — and supplies the key primary sources: Fleta and Bracton. The quoted passage from Fleta (*si [charta] communes sint, duplicari debent, quod quilibet habeat partem suam*) is genuinely instructive: it frames the practice as an obligation arising from the communal or mutual character of the charter, and explains the purpose (each party possessing his part).
Burrill's truncated entry for *conventio duplicata* leaves the researcher wanting a fuller treatment of what distinguished a duplicated covenant from other covenant forms, but the cross-reference is sufficient to trace the concept into treatise literature. No other standard historical legal dictionaries give *duplicare* significant independent treatment; it is more fully discussed in treatises on conveyancing history than in dictionary form.
Jurisdictional Note
*Duplicare* as a formal conveyancing term belongs primarily to medieval English and continental civil law practice. Its relevance to modern jurisdictions is historical rather than operative; no contemporary common law system uses the Latin term in practice, though the underlying concept — counterpart originals each held by a contracting party — remains standard.